Though there are a few exceptions, most cacti and succulents prefer dry growing conditions. It is possible to plant entire beds or borders using these drought-tolerant plants. However, I prefer to interplant the hardy cacti and succulents with annuals and perennials that tolerate the same kinds of growing conditions. The following flowers are some that work very well with cacti and succulents.
Any number of suitable species is available as bedding plants in the spring. These are sold in garden centers and other retail stores.
Ageratum, sometimes known as floss-flower, is an excellent companion plant. Typically these feature fluffy flowerheads in various shades of blue.
Statice is one of my favorite drought-tolerant annuals. This is great for interplanting with cacti and succulents. At the end of the growing season before the first frost arrives, I cut the stems for use as an everlasting.
For the cooler months, pansies and violets are a good choice. Usually, these will overwinter and bloom again the following year.
Other cool season flowers that are good for planting with cacti and succulents include snapdragons, California poppy, flowering cabbage and kale, and sweet alyssum. For the most part, sweet alyssum and California poppy can be direct sown in the garden. The others may require too long to bloom when they’re started from seeds. So I usually buy these plants.
For whatever reason, the flowering cabbage and kale are grown and sold in the fall and early winter months. Because they tolerate cool temperatures, they should be a good choice for cool season spring gardens.
A number of other annuals could be direct sown in into flower borders where cacti and succulents are growing. These would include pot marigold, cosmos, marigold, zinnia, globe-amaranth, and cleome or spider flower. Whether you want to do this or buy plants may depend upon the length of your growing season. Here in western North Carolina, the season is long enough that I have plenty of time to plant seeds outdoors.
Several drought-tolerant companion plants for cacti and succulents are actually perennials that will bloom the first year from seed. This is true for the blanket flower or gaillardia, a plant that is considered a short-lived perennial. Foxy foxglove is also in this category, although it is actually a true biennial. Unlike most foxgloves, this variety blooms during the fall of the first year, and returns again to bloom the following spring and summer before they die. Foxgloves readily self sow, so you only need plant them once.
In addition to these annuals or perennials, there are some annuals that are best purchased from nurseries or garden centers. These would include celosia, coleus, dusty miller, impatiens, vinca, petunia, scarlet sage, begonia, and the many different kinds of verbenas. Typically, these are challenging to grow from seed, or must be started several months indoors prior to the last expected spring frost.
With all of these drought tolerant flowers, it is easy to mix and match them with our hardy cacti and succulents in flower beds and borders.